Are hydrogen atoms different from oxygen atoms?

Yes. That's the main reason why the properties and characteristics of hydrogen
are completely different from the properties and characteristics of oxygen. 

For only one example, almost 1/5 of the air you breathe is oxygen, and
when you breathe it in, your body can live on it.  But practically zero of
the air you breathe is hydrogen, and even if you get a tank of it and
breathe it, your body can't.

Almost every atom of oxygen has 8 protons and 8 neutrons in its nucleus.
Almost every atom of hydrogen has 1 proton and no neutrons in its nucleus.

Oxygen doesn't burn in oxygen, but carbon does.  When that happens,
the carbon atoms and the oxygen atoms combine, and form molecules
of carbon-dioxide.

Hydrogen does burn in oxygen.  When that happens, the hydrogen atoms
and the oxygen atoms combine, and form molecules of water.

A few other things that all have completely different atoms are helium,
silver, neon, sodium, chlorine, iodine, iron, silicon, nitrogen, gold, tin,
copper, nickel, mercury, aluminum, lead, calcium, and uranium.

All of these substances that have different kinds of atoms are called
"elements".  All together, there are 92 different ones that are found in
nature.  All other substances are called "compounds" ... they're made
of atoms of different elements.  Things like salt, water, plastic, sugar,
and alcohol are all compounds, and there are thousands of other ones.
 
It's all pretty interesting. It's called "Chemistry".

Where is the diagram? you need to be more specific in your question so we can you